Aerial torpedo



March i, 3949. H. T. PYLE :E1-Al.

AERIAL TORPEDO 2 Sheets-Sheet l Find oct. 5, 1942 f1 EEN .MMA "n" Huh.

IN VEN -ro/es flown/ea 7'. PYLE ana HND/@sw 6. vv/ymv Tron/ways.

March l, 1949., H.T.PY| E ETAL 463m AERIAL TORPEDO Filed Oct. 5, 1942 2Sheets-Sheet 2 zag) ' /aof INVENTORS /fowqo ryw /7//0 /yopfw s. www

ATTORN EYS Patented Mar. l, 1949 AERIAL TORIPEDO Howard T. Pyle andAndrew G. Tynan, Kokomo,

Ind., assignors to Detroit, Mich., a

General Motors Corporation, corporation of Delaware Application October5, 1942, Serial No. 460,760

8 Claims.

This invention relates to control mechanism for a torpedo andparticularly an aerial torpedo adapted to be released or launched froman airplane or airship.

The type of control mechanism to which the present invention relates isshown, for example, in the copending companion application of Robert H.Hill and James A. Guyton, Serial No. 461,370, filed Oct. 9, 1942 whichdiscloses a torpedo provided with a control mechanism adaptedautomatically to maintain the torpedo in a substantially direct path oftravel toward a substantially constant light source which illuminatesthe target. The control mechanism is contained in a unitary housingattached to the torpedo. The housingY hasv ns and steering rudders forguiding purposes and ailerons for stabilizing the torpedo during itsflight. The ailerons are controlled by a compass in such manner thatrotation of the torpedo is prevented during downward night. Thedirection of flight is controlled by the steering rudders` which areoperated by servo-mechanisms controlled by four spaced photo-electriccells mounted at the. head end of the torpedo.. Deviation from theproper course of flight causes certain cells to become more active thanothers. Consequently the servomechanism operates to bring the torpedoback into the correct course for landing upon the lluminatedV target.

The housing of the Hill and Guyton application carries four ruddersmounted in pairs upon two shafts at right angles. Each shaft may bedriven by a constantly operating servo-motor by either of two geartrains connectible with the motor by a magnetic clutch. Therefore thereare four clutches and four photo-electric cells individually controllingthese clutches. When one cell becomes more active than the others, oneof the rudder shafts will beconnected with the electric motor due to theenergization of the magnetic clutch associated with the more activecell. The shaft will turn suiiiciently to cause the torpedo to bebrought back into the proper course. The control system providesl thatthe two shafts may operate at the same time to correct for deviationfrom course; but the magnetic clutches controlling the operation of thesame rudder shaft cannot operate at the same time.

The Hill and Guyton system of control isrsuccessful when the intensityof ambient illumination is relatively low. That is, the illuminatedtarget should be clearly distinguished from any general illuminationaround the target. The present' invention is concerned with theelimination disclosed in the aforementioned of effects upon the controlapparatus dueto general illumination regardless of its intensity.

Therefore it is among the objects` of the present invention to provide atorpedo with control mechanism adapted automatically to maintain thetorpedo in a substantially direct path of travel toward a source ofintermittent light flashes in the direction of which the torpedo Wasinitially launched. These intermittent light dashes on or near thetarget may be provided in various manners. A specially designed andconstructed flareV may be dropped onv the target previous to thelaunching of the torpedo, said nare giving oi ashesof predeterminedintensity and at predetermined intervals. Another Way to provide theguiding light flashes is to have the airplane which Will launch thetorpedo, equipped with ay search light adapted to cast strong rays oflight toward and upon the objective, said light flashes occurring atcertain intervals so as to be adapted to cooperate with the controldevice of the present invention to guide the torpedo toward itsobjective or target.

The dii'erences between the control circuits copending, application andthe one disclosed in the present application are as follows:

The control circuit of the copending application requires a constantsource of light at the objective to render it operative for controllingthe flight of the torpedo.

On the contrary, the control circuit of the present application isdesigned and constructed to be responsive only to intermittent flashesof light of predetermined intensity, intervals and duration. A constantsource of direct or ambient light has no effect thereon.

For instance, when a torpedo, equipped with .-.ie control device of thecopending application, is to be launched upon an objective there mustrst be placed upon said objective a light inthe form -of a are,incendiary bomb or any other suitable light source from which a constantlight beam of suicient intensity emanates. With a torpedo equipped withthe control circuits of the present invention a source of light givingoi intermittent flashes must be used. The light flashes, mustv be of asufficient intensity and must reoccur at predetermined intervals,dependent upon the characterk and design of the electrical units in thecontrol device. The control circuits of the present application providefor elimination of the eiiiects` of constant illumination.v upon thephotonelectric cells and passes to the conof the one shown, the powersupply being in common to both control circuits.

Fig. 2 is a diagram showing the circuits of the heater elements of allof the tubes used in the circuit of Fig. 1. l

Fig. 3 is a chart showing the relative timing of the light intervals,duration of light flashes, duration of relay energization anddeenergization and the resultant operation of a magnetic clutch.

Fig. 4 is a plan View in outline of a torpedo equipped with the presentinvention.

Fig. 5 is a side view in outline of the torpedo shown in Fig. 1, thevarious elements in the casing attachable to the torpedo being shown intheir proper relative positions.

Referring to the drawings and particularly to the Figs. 4 and 5 thereof,the torpedo itself is designated by the numeral X having a casing 26Xattached thereto by any suitable manner, as for instance bands 28X.Within the casing 26X there is provided the control mechanism forcontrolling the flight of the torpedo after it is launched from the yingairplane or airship toward the illuminated target.

The front end of the casing 26X is open and in its open end of thecasing the optical mechan-4 ism of the control apparatus is secured.This optical mechanism includes four photo-electric tubes, and forpurposes of this description two are referred to, being numbered 93IAand. 93|B.

The rear end of the casing is stream-lined and has a group of oppositelydisposed fins 29A and 29B, 29C and 29D. These ns are at 90 one toanother.

Elevators 30A and 30B and rudders 30C and 30D are pivotally secured onthe casing so as to be in alignment with the respective iin and capableof being hingedly moved out of alignment with the respective iin ineither direction. These fins and their respective aligned steeringmembers form the steering mechanism for the torpedo during its flight.

The casing 23X is also provided with oppositely disposed wings SIX and32X respectively. Each wing has a hinged aileron, the aileron on thewing 3IX being designated by the numeral 33X, and the one for wing 32 bythe numeral 34X.

The steering rudders and elevators are actuated by a servo mechanism 10Xwhich may be of any suitable type of servo mechanism, for instance thetype illustrated, described and claimed in the copending application,Serial No. 461,370, filed Oct. 9, 1942, by Robert H. Hill and James H.Guyton. This servo mechanism 10X is controlled in turn by the opticalapparatus previously described as being located at the front open end ofthe casing 26X and comprises a plurality of photo-electric tubes amongwhich are the ones referred to by the numeral 93|A and 931B.

' The ailerons 33X and 34X on the respective wings 31X and 32X areactuated and controlled by a servo mechanism X of the same type as theservo mechanism 10X, this aileron actually being mechanically controlledby a compass 50X. The source of electric power is shown in the form of astorage battery 60X.

As has been previously mentioned, the guiding rudders and elevators areactuated under the control of an optical system including photoelectrictubes. When the torpedo is launched from the flying plane or airship,the switch 64X is automatically operated to connect the storage battery60X with the entire electrical system, rendering the system operativeimmediately upon launching. Preparatory to launching the compass 50X isset so that the photo-electric tubes are directed toward the illuminatedtarget at a predetermined or certain directional relation relatively tosaid target. Light rays emanating from the target and in this instance,particularly intermittent ashes of light rays strike the optical system,and as long as the intensity of the light rays strike all of thephoto-electric cells equally, a balance is maintained and no actuationof the steering mechanism is effected. However, as soon as the torpedoveers in any direction right or left, or at to these directions, thenthe balance of intensity of the light rays striking on the opticalsystem is upset so that one tube will receive more intensive light raysthan another whereby this tube will be rendered efective to set itscontrol mechanism into operation for actuating the proper steeringdevice so that the torpedo is again brought into the proper path.

The compass control during this time will prevent rotation of thetorpedo about its longitudinal axis during its flight, a feature whichis absolutely necessary for the proper effective operation of thetorpedo. It will readily be seen that if the torpedo were permitted torotate about its longitudinal axis, the optical system would, if suchrotation is complete about the axis, rotate in a circle whose radialdistance would be equal to the distance between the center of thetorpedo 25X and the casing 26X. Traveling in this circle would entirelyupset equilibrium, for the various photo-electric cells would at alltimes be changing their relative positions to the target and would berendered effective in quick successive intervals which wouldcorrespondingly actuate the various guiding rudders and elevators inquick succession, thereby throwing the torpedo into an unimaginable spinand consequently destroying its effect. With the compass -controlcooperating with the optical control so that any tendency of the torpedoto rotate is substantially prevented and immediately corrected, thedirectional relation of the optical system with the target as set at thetime of launching, is practically maintained during the entire night ofthe torpedo toward its illuminated target and consequently completecontrol is maintained during its entire flight.

This compass control which acts upon the ailerons 33X and 34X to preventturning of the torpedo about its longitudinal axis during its fallingflight after being launched from an airplane, is identical with the onedisclosed in the aforementioned copending application Serial No.461,370. The compass 50X is cradled in a gimbal ring 51X so that, bygravity, the axis of its operating parts, especially its polarcontrolled member, is constantly held at substantially right angles tothe horizon. Any tendency of the torpedo to rotate about itslongitudinal axis while dropping toward its target will rotate thecompass and thereby move its polar controlled part relativelyV to theNorth Pole causing it to rotate due to polar attraction. As the polarcontrolled part rotates it aiects certain parts in the compass whichcause the servo mechanism 80X to become operative to adjust the ailerons33X and 34X. Thus when the torpedo starts to rotate in one direction thecompass control adjusts the ailerons to cause the torpedo to be rotatedin the opposite direction and be returned to normal position. Eachturning tendency of the torpedo is therefore counteracted by theadjustment of the ailerons.

Referring particularly to the Figs. l and of the drawings the numerals93|A and 535B designate the two multiplier photoelectric tubes adapted,under the influence of intermittent light beams on the objective ortarget, to eiect control of the operation of the servo-mechanism whichactuates two of the four rudders on the torpedo for steering the torpedotoward said objective. This intermittent light beam may be provided byintermittent are dropped on or near the objective or by a search lighton the airplane giving intermittent illumination of the target. Thisintermittent illumination is reflected back upon the photo-electrictubes SSlA and 93| B to cause their proper excitation for controlpurposes.

The photocathodes o of the tubes 53m and 931B are supplied with highvoltage unidirectional current through a `circuit which includes wire232, filter 235, transformer secondary 225 and half-wave rectier tube 2X 2. Secondary 226 is part of a power supply unit having a D. C. to A.C. converter 225 is connected through a lter 22lA with the l2 voltbattery 22! which is the source of electrical power for the entirecontrol device. The tubes SMA- are of the 9 stage multplying type,having nine dynodes numbered from 1 to 9 and having a ring of voltagedividing resistances marked R. The anodes lil of said tubes areconnected respectively by wires 25 and 23 and condensers 2i and 24 withthe grids 22 and 25 of the tubes GSFE. These condensers 2i and 24 are soconstructed and arranged that they will pass only pulsating current toltheir respective grids 22 and 25, any direct current being blocked o`and caused to flow to ground G through the respective resistances 3| and33 connected to wires 25 and 23 ahead of the condensers 2i and 24.Because they prevent the passage of direct current, these condensers arecalled blocking condensers; however, they may also be termed couplingcondensers inasmuch as they also couple the anodes I5 with therespective grids 22 and 25 of tubes 5SF5A and B for the passage ofpulsating current. The cathodes 26 and 21 of tubes 5SF5A and 6SF5Brespectively are connected together through two load resistances 28 and2S both of which are connected to ground G through wire 30. Between thiswire 3% and the grids of tubes GSFSA and B are connected two grid returnresistances 32 and 34 respectively.

Tube 6SF5A has a plate 35 connected toone side of a D. C. blocking andA. C. coupling condenser 37 the other side of which is connected withthe grid 39 of the tube 2550A which may be termed a trigger tube.Likewise tube BSFSB has its plate 3S connected to the D. C. blocking andA. C. coupling condenser 38 which is also connected to the grid 45 thetrigger tube 255GB. Plates 35 and 35 are connected through respectiveloadv resistances 95 and 95 with a lter 233 of standard design saidfilter being connected 6. with afull wave rectifier 6X5B fed by thesecondary winging 227 of the transformer. The grids 39 and 4D of thetrigger tubes 2550A and 235GB respectively are connected through gridreturn resistances 45 and 45 connected with adjustable resistances 4'!and 48 connected between the negative pole of the battery 22! and groundG. These adjustable resistances 4l and 4B form what is termed a balancerfor equalizing the action of trigger tubes 2050A and 2055B respectively.Adjustment of the grid balancer resistances 47 and 48 determines thegrid bias on the tubes 2550A and B respectively and hence determinestheir triggering point, or in other words determines the amount of pluspotential which must be impressed upon the grids 39 or 45 before thetubes 2050A or 2il5B pass current.

The control relay designated as a whole by the numeral 55 has twoelectromagnets 53 and 54 adapted to actuate a walking beam armature 65.One end of each winding of electromagnets 53 and 54 is connected to theother as at 55. The other ends of said windings are connectedrespectively to plates 5l and 52 of the tubes 2050A and 28MB. A wire 5lleading from the juncture point 55 of one end of said electromagnet,windings, connects with one end of the magnet winding 55 of an overloadrelay 60; A condenser 5| and resistance 52 connected in shunt withwinding of magnet 53 provides a timing device adapted to control theaction of this electromagnet while a similar condenser 53 and resistance64 perform the same function for the electromagnet 5,4.

The relay armature 55, grounded at G, has one end normally engagingcontact 68 and its other end contact 1l. Contact 65 is connected withcathode 42 of tube 255GB through wire SS. Contact 'Il is connected withthe cathode 4! of tube 2550A. A contact 5l is adapted to be engaged bythe grounded armature 55 when it is attracted by the energizedelectromagnet 53. While contact 61 is engaged by the armature 55, saidarmature is disengaged from contact 'Il while remaining connected withcontact $6. Another contact 'lll of the relay is engaged by the armature65 when it is attracted by energized electromagnet 54 at the same timeremaining connected with contact li but severing connection with contact66.

Normally the clutch magnet coils l5 and 'i6 are disconnected frombattery 22l. The movement of armature 55 toward magnet 53 whenenergized, causes clutch magnet coil i5 to be connected with the battery22! through contacts 'F2 and 13 of limit switch unit lla. When armature65 moves toward magnet coil 54, the clutch magnet coil 'I6 is connectedwith the battery 22l through the contacts 'l1 and 'I8 of limit Switchunit 7l The limit switch unit lla is operated by a rudder operatingshaft 'i9 which is caused to rotate in either direction by a servomctor(not shown) depending upon which of the two clutch magnet coils 15, 'IGis energized. The limit switch Ha comprises an actuator cam 32 mountedon the rudder shaft "l5 which shaft when rotated in one direction bysaid servo-mechanism rotates two of the rudders in one direction; andwhen rotated in the other direction, the shaft rotates said two ruddersin the opposite direction. The two sets of normally engaging contactsl2-l3 and 'll- '58 are arranged on diametrically opposite sides of therudder shaft 79. Contact i3 is connected to one end of the winding ofelectromagnetic clutch 'l5 the other end being connected to the negativeside of the battery 22|. Likewise contact 18 is connected to one end ofthe winding of electromagnetic clutch 16 which is also connected to thebattery as shown. A flexible arm 10 carries contact 12 and a similarflexible arm 80 carries contact 11. These two arms 10 and 80 are engagedby the cam 82 at a predetermined point in the counterclockwise orclockwise rotation respectively of the said cam and its shaft 19 wherebythe rotation of the two rudders connected to said shaft is limited ineither of said directions. Flexible arm 10 of the limit switch 1Ia isconnected to contact 61 -while arm 80 is connected to contact 10 of thecontrol relay.

The overload relay has an armature 9D yieldg ably urged to engage acontact 9| connected to the end of the relay winding 58 opposite that tovwhich the control relay windings 53 and 54 are connected by wire 51. Atiming device comprising a condenser 60a and a resistance 60h isconnected in shunt with magnet winding 58 this device automaticallytiming the operation of this relay. The armature 90 is connected througha resistance 92 with a full wave rectifier 6X5A fed from the secondary93 of the transformer.

In order to simplify the circuit diagram Fig. 1, all of the heatingunits of all of the tubes used are shown with their circuit connectionsin Fig. 2.

Fig. 3 is a timing chart, the spaces b-b representing the frequency ofthe light flashes to effect control. For the sake of comparable valuesthese spaces b will represent .l second denoting that the time betweensuccessive, intermittent flashes is .l of a second. The letter cdesignates the time length ing devices, would be excited for a period of.08 of a second iwhich is designated by the letter d, the differencebetween intervals b and d denoting the time during which the relay lightflashes energizing one or the other tube 93 IA or 931B to render itpredominating will cause clutch magnet energization over the constantperiod denoted by the letter e, the clutch magnet, however, becominginoperative when tubes 93|A and 93|B are again brought into balance byequal excitation or equal exposure to the light rays.

As long as the torpedo, after launching, approaches the objective sothat the periodic light rays emanating therefrom fall substantiallyequally upon tubes 93 |A and 93 IB, both amplifying tubes SFSA and EFSBwill be concurrently energized sufliciently to cause trigger tubes 2050Aand 20.59B to pass current through the magnet coils 53 and 5Asimultaneously. If the relay magnet windings 53 and 54 aresimultaneously energized, the armature would continue in normal positionand the plate circuits of the tubes 2050A and B would never be broken.However the instant both tubes 2050A and B pass current, the currentpassed is suflicient to cause overload relay 60 to separate contacts 9|)and 9| and thus to break the plate circuits of both tubes 2959A and B.So long as the cells 93|A and B are both excited simultaneously to adegree sufficient to cause tubes 2950A and B to become simultaneouslycon ducting, this cycle of operation will be repeated and the relay 66will operate as a buzzer. Therefore the control relay 55 remains inneutral so long as the excitation of the photo cells is substantiallyequal.

If, for any reason. the torpedo should veer from its directed coursetoward the objective then the intermittent light flashes would notstrike of the iiash which would be approximately .00001 second. Thecontrol relay, due to its timis inoperative. AniT the two photoelectrictubes 93IA and93IB with equal intensity and consequently one of saidtubes would be excited to a greater degree than'the other. For instance,let it be assumed that the torpedo has veered from its directed coursetoward the objective so that the tube 93|A receives a greater intensityof said intermittent light rays than the tube 93 IB. At the same timetube 93 IA might receive ambient light rays which are of a constantvalue. Tube 93|A will immediately be excited to a greater degree thantube 93IB. In fact under some circumstances tube 93IB would receive nocontrolling light rays whatsoever. Now, with tube 93|A being excited bylight rays some of which are of an ambient, constant nature while theothers, actual controlling rays occur periodically, a current will beproduced in the wire 20 leading from the anode I0 of tube 93IA saidcurrent being of a constant and pulsating character. The constant or D.C. component of this current is blocked by the condenser 2| and causedto return to ground via the resistance winding 3|. The pusating or A. C.component of t-he current in wire 20 passes through the condenser 2|,now acting as a coupling condenser, to the grid 22 of the tube 6SF5A.Excitation of this grid by pulses causes pulses of current to ow fromthe full wave rectifier tube 6X5B and its iilter 233 through theresistance 95 to plate 35 and across the tube to its cathode 26, cathoderesistance 28 back to ground G. Excitation of the tube BSF5A as justdescribed provides an amplification of the pulsating voltage received atgrid 22 and impressed amplied pulsating voltage upon the grid 39 of thetrigger tube through the coupling condenser 31 which serves also tolprevent passage therethrough of the D. C. current from filter 233, butallowing passage of the amplified A. C. voltage from tube IiSFSA to thegrid 39 of the trigger tube 2050A which renders the tube 2050Aconductive or what may be termed triggerable. This grid 39 is connectedto the grid return resistance 45 which adjustably engages the balancerresistance 41. Adjustment of the resistance 45 along the balancerresistance 41 determines the grid bias on tube 2050A and hencedetermines its triggering point, in other words, the amount of pluspotential which must be impressed upon the grid 39 before the tube 2050Awill be conductive or pass current.

When tube 2050A becomes conductive or reaches its triggering point,current will flow from the full wave rectifier tube 6X5A to the armatureof the overload relay 60 thence through the contact 9|, normally engagedby the armature, magnet winding 58 to the junction point 56, controlrelay magnet 53 to the plate 5| of trigger tube 2050A and after passingthrough said tube to contact 1I, armature 65 and back through ground G.This energizes the control relay magnet 53 to attract and move thearmature 65 counterclockwise regarding Fig. 1, thus causing the armatureto engage contact 61 and break its engagement with contact 1|, therebyinterrupting the plate circuit of tube 2050A and causing it to becomenonconducting until again triggered as the result of a succeeding flashof light. When the armature 65 engages contact 61 the circuit acrosslimit switch contacts 12--13 and the electromagnet clutch 15 iscompleted which renders the rudder operating servo-mechanism operativeto move the rudders in the direction necessary to again return thetorpedo to its directed course toward the target when the two tubes 93|Aand 931B will again receive the intermittent light rays equally.Operation of .the servo-mechanism rotates the shaft 'i9 and the cam 82counterclockwise, the cam-82 when reaching a predetermined pointengaging blade 'i9 and moving it to separate its contact I2 from Contact13 to break the clutch magnet circuit .and render the servo-mechanisminoperative to continue rudder adjustment.

As the armature 65 of the control relay 55 disengages contact 'il due toenergization of relay magnet 53, the circuit through the ytube 2050A isbroken rendering said tube inoperative and :at the same timeinterrupting the :ow or energizing current through the relai/magnet 53.This, if no other means were provided, would quickly render the relaymagnet ineffective to hold the armature in attracted position resultingina substantially immediate discontinuation of clutch energization andservo-mechanism operation. However, in the present arrangement'there isprovided a circuit in shunt withthe relay magnet winding 53, thiscircuit including -a resistance 82 anda 'condenser 6l. The action ofthese upon the relay magnet is analogous to -the vaction of a dash-pot,that is, this shunt circuit retardsthe deenergization of the relaymagnet 53 so `that the armature is retained in its attracted positionover a longer period even though the tube current is completely cut oi.This is clearly indicated in the Fig. 3 where c designates the length ofthe light flash and thus the substantial length of energization while ddenotes the extended time of magnet excitation and armature attractionor in other words the duration of closing of contacts 61 and S5.

When armature S5 is returned to its normal position vwhere vit engagescontact 'l'l and has disengaged contact-S, then the tube '2050A is againready to respond to a light flash received Yby the tube 931A. Successiveflashes-occur at the rate b, Fig. 3, their time 'length is c and therelay magnet is eiTective over the period d. The intervals betweenlashes `being short, the time length of flashes exceedingly shorter andthe action of the electromagnet relay and electromagnetic clutch on thecontrary relatively slow, the operation of cluch magnet and theservo-mechanism controlled by it is substantially sustained duringeffective recurrent light indicated at e in Fig. 3.

As long as one or the other of tubes 93IA or 93IB is effective to causeoperation of relay 55, the vibrating relay is not 7depended upon torender the active trigger tube inactive. However, when both triggertubes 2055A and ZlB are equally excited and consequently endeavorsimultaneously to energize both -electromagnets 53 and 54 of relay 55then the relay 5D, active as a buzzer, tends to render both triggertubes 2050A and 2il5B inoperative. Attempted equal 'energization of therelay magnets 53 and 5@ renders the relay inactive; and thus, under thiscondition, contacts 6l and H are not engaged by the relay armature torender the electromagnetic clutches 'i5 and 'i5 effective.

Resist-ancres i3 and 44 are sufficiently high to limit the plate currentto avery 'low value when armature 55 separates from contacts 66 or 'ilso that the tubes 2559A and B will become non conducting by said Contactseparation, Resistances 43 and i4 serve to reduce sparking at thesecontacts.

It will be understood that the other two of the four multiplierphotoelectric tubes 93! series are provided with the identicalarrangement of tubes, relays, condensers, resistances and their circuits10 as has just been described and that they all work together in thesame manner to eiect operation of the servo-mechanism for purposes ofadjusting the other cooperating rudderson the torpedo for controllingits ilight in other directions.

In the foregoing the use of the term light is not to be construed aslimiting the device to the use of visible light. Any electromagneticradiation which will actuate photo tubes may be used, including infrared light, visible light, or ultraviolet light. By providing the lightsource and the lens system of the servo unit with vsuitable light ltersthe light source may be made invisible to the eye yet still capable ofoperating the servo control unit. The photo tube may also be of a typespecially sensitiveto :the type of light to be used.

The tubes Tubes 93! of which there are four in thecomplete system ofcontrol are referred to by their catalogue number and are obtainable 0nthe open market. The same is true of the tubes 6SF5 and 2050.

The various electrical units:

Experiments have proven that the electrical dimensions of the variouselectrical units as given below provide for satisfactory results:

The resistances marked R in tubes f93|A and B are each 100 M ohmsResistances 3l and 33 are each 100 M ohms Condensers 2l-24-'31 and 38are yeach 120 m. m. f.

Resistances 32--34-45-46 are each 470 M' ohms Resistances -95 are each270 M ohms Resistances 47-48 are each 25 M ohms Resistances i3- 44 areeach 1.2 megohms Resistances {i2- 64 are each 330 ohms Condensers 6I-f63 are each 10 mid.

Condensers 50a is 50 mfd.

Resistance 60h is 600 ohms The two condensers in filter 233 .are 20 mfd.

The resistance of lter 233 is 5600 ohms Resistance 92 is 150 ohmsSecondary winding 226 1350 v. 5 ma.

While the embodiment of the present invention as herein disclosed,constitutes a vpreferred form, it is to be understood that other formsmight be adopted, all coming Within the scopevof the claims whichfollow.

Whatis claimed is as follows:

1. In a control device for an aerial torpedo, the combination withsteering rudders on said torpedo; of a source of electric power; aservomechanism adapted to actuate vthe rudders; a multiplierphoto-electric tube adapted in response to a constant ambient light andalso in response to intermittent light rays impinging thereon, toprovide constant and pulsating currents respectively; a condenser forblocking the .current having a constant component .and for passing thecurrent having a pulsating component.; and a voltage amplifying tube,fed by the said pulsating current for passing current to rendereffective the rudder operating servo-mechanism whereby it Will aotuatecertain of said rudders in one direction.

2. In a control device for an aerial torpedo, the combination withsteering rudders on said torpedo; of a source of electric power; aservomechanism adapted to actuate the rudders; a multiplierphoto-electric tube adapted in response to a constant ambient light andalso in response to intermittent light rays impinging thereon, to

provide constant and pulsating currents respectively; a condenser forblocking the current having a constant component and for passing thecurrent having a pulsating component; an amplifying tube excited by thepulsating current for rendering it conductive to current from the sourceof power whereby said tube provides an amplification of the pulsatingvoltage received by it from the multiplier photo-electric tube; acondenser for passing only the pulsating component of the current fromthe amplifying tube; a trigger tube upon which said amplined voltage isimpressed; and means for rendering said trigger tube 'effectiveperiodically to eiect energzation of the servo-mechanism to actuatecertain of said rudders in one direction.

3. In a control device for an aerial torpedo, combination with steeringrudders on said torpedo; of a source of electrical power; aservomechanism for operating said rudders in one direction or the other;a tube adapted to be excited by intermittent light rays impingingthereon to provide pulsating current; a second tube adapted to amplifysaid pulsating current; a trigger tube excited by said amplifiedpulsating cur-- rent to render said tube conductive to current -from thepower source; and means rendered effective by said current iiow from thepower source through the trigger tube to render the servomechanismactive to operate certain rudders in one direction and to deenergize thetrigger tube.

4. In a control device for an aerial torpedo, the combination withsteering rudders on said torpedo; of a source of electrical power; aservomechanism for operating said rudders in one direction or the other;a tube adapted to be excited .by intermittent light rays impingingthereon to provide pulsating current; a second tube adapted to amplifysaid pulsating current; a trigger tube excited by said amplied pulsatingcurrent to render said tube conductive to current from the power source;and an electromagnet relay energized by the flow of current from thepower source through the trigger tube for concurrently closing acirc-uit through the servo-mechanism to render it active for movingcertain of said rudders in one direction only and for opening a circuitthrough the trigger tube to render said tube inactive.

5. Ina control device for an aerial torpedo, the combination with fourrudders arranged in cooperating pairs; a source of electrical power; amultiplier photoelectric tube for controlling each pair of rudders, eachtube being adapted in response to intermittent light rays impingingthereon to provide a pulsating current, an amplifier tube connected toeach multiplier tube and excited by said pulsating current to provide anamplified pulsating voltage; a trigger tube connected to each amplifyingtube and excited by said amplifled current to be rendered conductive tocurrent from the source of power; a double relay adapted to be energizedby the action of one or the other trigger tubes to renderservo-mechanism eective to actuate a pair of rudders in one direction orthe other and then deenergize the active trigger tube; and means forgradually retarding the deenergization and resultant return to normal ofthe active relay whereby said tube is reconditioned for anothertriggering cycle.

6. The invention as defined by claim 5 in which, however, a second relayis provided which is adapted successively to break the trigger tubecircuit to render said tube ineffective when both ltrigger tubes equallyenergize the relay and thus neutralize its effect in response to equalexcitation of the two multiplier photoelectric cells.

7. A device in accordance with claim 4 in which, however, the torpedo isprovided with stabilizing wings and adjustable ailerons; aservo-mechanismnormally maintaining said ailerons in neutral alignmentwith their respective wings; and a compass on the torpedo operative inresponse to turning of the torpedo about its longitudinal axis duringits descent flight to cause the last mentioned servo-mechanism to becomeoperative for adjusting the ailerons to counteract said turning of thetorpedo whereby the rst mentioned tube is substantially held in constantreceiving position relative to said intermittent light rays.

8. A device in accordance with claim 3 in which, however, the torpedo isprovided with wings each having an adjustable aileron; a servo-mechanismnormally holding said ailerons in normal alignment with their respectivewings, but operative to adjust said ailerons for causing the torpedo torotate about its lonigtudinal axis during downward flight toward thetarget against which the torpedo was released; a compass on the torpedo,having a polar controlled rotor; and means rendered effective byrelative rotation between the compass and its rotor in response torotation of the torpedo about its longitudinal axis during downwardflight for causing the last mentioned servo-mechanism to operate theailerons whereby the torpedo is returned to its norw mal flightposition, thereby substantially maintaining the rst mentioned tube inconstant light ray receiving position.

HOWARD T. PYLE. ANDREW G. TYNAN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,376,192 Dye Apr. 26, 19211,384,868 Sperry et al July 19, 1921 1,388,932 Centervall Aug. 30, 19211,418,605 Sperry June 6, 1922 1,792,937 Sperry Feb. 17, 1931 1,818,708Hammond Aug. 11, 1931 2,100,934 Berges Nov. 30, 1937 2,123,598 Vos Nov.22, 1938 2,165,800 Koch July 11, 1939 2,190,390 Thiry Feb. 13, 1940FOREIGN PATENTS Number Country Date V 305,571 Italy Feb. 9, 1933 339,479Italy Apr. 22, 1936 797,933 France Feb. 24, 1936

